Damaged wing covering around rivet: how, what, and can it be fixed?

K

kubark42

Well-known member
Joined
Mar 25, 2021
Messages
92
Location
Massachusetts
This plane (1998 Aurora 7ECA) had 23 years of perfect covering. Babied, stored indoors, and showroom quality even two decades later. I, its new owner, have it for less than 16 hours-- not even had time to fly it home yet-- and already this:

20210423_133439.jpg

Aside from being grossly unjust (come on world, I *just* got the plane!), it is also perplexing. I noticed the damage when trying to clean the bugs off after a two hour flight. I had cleaned the wing of bugs immediately before the flight, so I think I would have noticed damage if it had been there prior.

The mechanic who saw the picture said he thought is was caused by a bug. (Put on your best Kentucky accent and drawl "Well... we get some industrial sized bugs down here.") I thought perhaps it could have been a bird, but there was no evidence of blood and I didn't hear anything other than normal flight sounds.

The damaged area seems to be right on top of a rivet, which could point toward this being a very unlucky strike upon a part of the covering which is likely weaker than on the surrounding metal. It could also point toward a rivet problem.

It's located out toward the wingtip, so it's not due to propwash.

20210423_133110.jpg

If you look closely at the first picture, you can see how the paint is cracked. I think we're looking at zinc chromate underneath the fabric, thus the yellow color. But judging by the deeper blue around the yellow, it almost looks like the rivet might have pushed forward, instead of an external impact.

(The bubbly things are in fact bubbles, from the Dawn dishsoap I was using to clean the plane.)

Three questions:
  1. What is it we're looking at?
  2. How did it happen?
  3. How should it be fixed?
    1. Is the plane still airworthy?
 
Last edited:
I think what you see is the adhesive that holds the fabric on. at that point in the wing I think you would have two layers of fabric plus tapes over the fastener so fabric integrity probably isn't an issue. you could probably spot treat the damage with a UV protective layer, primer and then paint and it would be fine but ACA'S covering system is proprietary so you should check with them. Stewart Systems could also legally be used.

sorry to hear it but I tend to break things when I first get them also! good for you that it wasn't worse! 😭
 
and it could have been a dead on bug hit, maybe combined with a little bit of a bubble at that spot causing it to get damaged? maybe?
 
Thanks, @Bartman. Do you think that this penetrated through the fabric or is it just a paint chip knocked free?

A feature I had missed until just now is the fine line of scratches at the top of the damage. The picture is oriented with the LE parallel to the upper edge, so those scratches are forward of the damage, and parallel to the airflow. Considering that this damage is also on the curved part of the LE, it surely looks like I hit something on climb out. The edge of the object made brushing contact with the wing and then made full contact several milliseconds later. This is consistent with the way the paint on the forward edge is torn and forced towards the back of the plane.

Maybe instead of cursing being unlucky about the hit, I should thank my lucky stars that whatever it was hit a strong part of the plane instead of the middle of a panel.
 
Agree with Bart ... the dark blue discoloration looks like a prior repair.

I would start by trimming away the loose threads and paint flaps to get a better look at the damage. Since you are over metal on the LE, should be no issues with continued flight. In the short term the damage is cosmetic.

To me it looks like a rock was kicked up. That's the only thing I can imagine would make a mess like that. Take a look at your prop for any nicks. Could also be someone else's aircraft threw a rock and it hit yours. Finally, is there any possibility it is hangar rash?

AFAIK the factory finishing system then was urethane paint based, so repair is whatever that requires. Probably strip to fabric, glue on patch with 1" overlap, prime and repaint. Your service manual should have a section on fabric repairs.
 
i keep looking at it, now I'm thinking someone put a schmear of epoxy over the ding. @kubark42 , is there a clear coating of epoxy over the bare fabric as if someone tried to put a protective shell over the spot? a local A&P might say to just put a piece of speed tape over it for the time being to keep it from accumulating more dirt or damage from airflow. The fabric is glued to the aluminum there so there isn't much worry about an expensive repair. the worst that will happen, like Ed said, is someone will have to work through the upper layers with some sandpaper and then build it back up to have UV protection and then primer and the matching top coat. It shouldn't cost much and you could probably go indefinitely with speed tape for $0. You could make a nice neat circle of speed tape and tell people it's a new type of sensor or something. airborne COVID detector maybe?
 
The prop does have a ding from sometime back. I found a picture taken during the pre-buy which hints that this damage was indeed present prior. Two mechanics and three pilots all missed it, if that gives an idea of the scale and visibility of the damage.

The prop has a ding in it, and while I can believe this could be a thrown rock, the scratches are aligned with the airflow direction so I feel more likely it's something from someone else.

The bubble which I thought was soap is in fact permanent, so I very much like the epoxy theory. The local A&P laughed and said to slap some duct tape on it. I used painter's tape because it matches the color a little better. :D

Thanks for the input everyone. I don't know much (yet) about covering technology and it's comforting to know that this really is a nothingburger. And it's a huge relief to know I didn't screw something up on the very first day!
 
Last edited:
Always irritating to get that first ding on your shiny new toy, especially on the first day! But yeah, totally cosmetic, and should be a simple fix. You got lucky that it's on the metal. A tear on the fabric between ribs would need to be fixed and would be more involved. The patch would have to span both adjacent ribs.
 
Bartman said:
any update on this?
Click to expand...

We finished our delivery flight last night and the wings didn't fall off. The blue painter's tape that we used to protect the area from UV stayed on for the entire flight, so that's good!

130kts sustained, thanks to a 45kt tailwind. Averaged 5.4g/hr, including climb and descent.

Before departing I had called ACA, but they haven't called back yet. Now that we're safely down, I'll reach back out to them and see what they say and who they recommend.
 
Had a nice call with Chad at ACA today. He confirmed that the plane was made with Ceconite 102 nd that the green w see in the picture is almost certainly the adhesive used on the fabric. The upshot is that it sounds like it's a pure cosmetic issue, and that the paint used in 1998 was Superflite. I even got the exact color, Maule Blue.

Unfortunately, they don't have any kind of touch-up kit I could get, so I'll have to hope I can find it from Superflite.
 
Superflite doesn't have a touch-up kit, and the smallest they sell is a pint. Seems kind of overkill for a pinkynail-sized chip. In fact, that's probably the exact reason why the previously repair wound up with a slightly different shade.

Unless someone has a better idea, I'll try to find some matching fingernail polish and apply that as touchup.

What an emotional rollercoaster from "Oh, my god, is my brand-new plane airworthy???" to "Huh, i guess I'll stop by TJ Max as I walk home from work." 🙃
 
Might try a hobby shop? But model paints cost way more per ounce than real airplane paint.

We have found a Rustoleum rattle can color that is dead nuts for Bahama Blue on a Super Cub. I am always fixing wingtip boo-boos on that one. Try also Dupli-Color. Auto parts store, in rattle cans.

I would fill with Bondo, sand smooth, prime, sand again, and then mask with tape cut with pinking shears for the final coats. The edges then look like surface tape edges. I have never mastered the art of blending.
 
Yes. They make an edge in the paint that is indistinguishable from pinked-edge surface tape. I realize that ACA uses straight tape, but again my experience is that straight tapes often fail more quickly than do pinked tapes. Almost all fabric covered airplanes except ACA use pinked edge tapes.
 
Pinked edge is better on fabric areas. I don't think it will matter on the leading edge surface, and it will look worse.

From what I understand, there are 3 different Superflite systems. The original was dope, then urethane, then a different urethane. Any idea which one you have?

Take a little bit of the coating debris and put it in acetone. If it dissolves, it is dope based. If not, it is urethane. If dope, that is easy to fix with Randolph dope, which is nearly idiot proof.

If urethane, I would look hard at Stewart system. It is approved for repairs on all systems, and is water based so no health issues. Their website has an extensive FAQ with lots of comments on patching Superflite. I met the owner at SnF and was impressed. Very helpful and full of useful info.
 
You must log in or register to reply here.
Back
Top